220181-42-0Relevant academic research and scientific papers
Asymmetric Steering of Oxa Diels-Alder Reactions with Silyloxydienes Employing Proline Esters as Chiral Auxiliary Groups
Blaeser, Edwin,Kolar, Patrik,Fenske, Dieter,Goesmann, Hellmut,Waldmann, Herbert
, p. 329 - 334 (2007/10/03)
Chiral aldehydes 4a,b, obtained by the ozonolysis of the corresponding N,N'-fumaroylbis 3 react in the presence of lanthanoid chelate complexes Eu(fod)3 or Eu(hfc)3 with silyloxydienes 7 or 12 to give δ-lactones 10 or dihydro-γ-pyrones 13 with very high diastereomeric ratios (up to 99:1).The absolute configuration of the predominating diastereoisomer of compound 10b was unequivocally determined by X-ray structural analysis.Keywords: Asymmetric synthesis; Chiral auxiliaries; Cycloadditions; Lanthanides; δ-Lactones
